Artificial leather of ethylene-propylene copolymer and manufacturing method thereof

ABSTRACT

The present disclosure provides an artificial leather including a fabric layer and an ethylene-propylene copolymer (EPM) layer attached to the fabric layer. The EPM layer is an EPM composite layer including an EPM foaming layer and an EPM surface layer. The present disclosure further provides a method for manufacturing the artificial leather, and a shoe structure including the artificial leather.

BACKGROUND 1. Field of the Disclosure

The present disclosure relates to an artificial leather and amanufacturing method, and more particularly to an artificial leathermade by environmentally-friendly processes, and a manufacturing methodthereof.

2. Description of the Related Art

Conventional artificial leather may be manufactured by a dry process ora wet process. The wet process involves impregnating or coating atextile with a resin solution including resin (e.g., polyurethane),organic solvent (e.g., dimethylformamide), surfactant, colorant, filler,etc. Then, the organic solvent may be replaced by water, so as to formpores in the resin. The resin is then solidified, thus forming theconventional artificial leather. In the dry process, a resin solution iscoated on a release material. After it is dried, a paste is applied onthe resin, and the resin is attached to a textile. The resin is thenmatured at a specific temperature, and the release material is removedto obtain the conventional artificial leather. However, both dry and wetprocesses involve the use of organic solvents such as dimethylformamide.Although these organic solvents can be recycled and reused, therecycling equipment is quite expensive, while the recovery rate may notbe high. Moreover, conventional artificial leather cannot meet therequirement of zero detection of organic solvents.

An improvement of the aforementioned processes may include heat presslaminating or extrusion laminating polyurethane onto a textile. However,the resultant artificial leather is heavy, and has a stiff hand feel andrubber-like appearance. It is also uncomfortable to wear, and notcompletely recyclable.

SUMMARY

To address at least some of the aforementioned issues, the presentdisclosure provides an artificial leather which can be manufactured byenvironmentally-friendly processes. The artificial leather islight-weight, and provides a favorable hand feel and leather-likeappearance. The artificial leather is also comfortable to wear, and iscompletely recyclable.

The present disclosure provides an artificial leather including a fabriclayer and an ethylene-propylene copolymer (EPM) layer attached to thefabric layer. The EPM layer is an EPM composite layer including an EPMfoaming layer and an EPM surface layer.

The present disclosure further provides a method for manufacturing theaforementioned artificial leather including: providing the fabric layer;providing the EPM layer; and attaching the EPM layer to the fabriclayer.

The present disclosure further provides a shoe structure including theaforementioned artificial leather.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross-sectional view of an artificial leatheraccording to a first embodiment of the present disclosure.

FIG. 2 illustrates a cross-sectional view of an artificial leatheraccording to a second embodiment of the present disclosure.

FIG. 3 illustrates a cross-sectional view of an artificial leatheraccording to a third embodiment of the present disclosure.

FIG. 4 illustrates a cross-sectional view of an artificial leatheraccording to a fourth embodiment of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 illustrates a cross-sectional view of an artificial leather 1according to a first embodiments of the present disclosure. Theartificial leather 1 includes a fabric layer 11 and anethylene-propylene copolymer (EPM) layer 12 attached to the fabric layer11.

For example, the artificial leather of the present disclosure may beused in clothing, shoes, hats, accessories, furniture, wall decorations,etc., or raw materials or semi-finished products. Alternatively, theartificial leather may be used in handicrafts or for other purposes,which are not limited by the present disclosure. In one embodiment, theartificial leather may be a part of a shoe structure, such as a part ofor the entire shoe upper in the shoe structure.

In one embodiment of the present disclosure, the fabric layer may be anytype of fabrics, such as woven fabrics or nonwoven fabrics. In oneembodiment, the fabric layer is a nonwoven fabric. The term “nonwovenfabric” used in the present disclosure refers to a sheet, web or batmanufactured by directionally or randomly oriented fibers, bonded byfriction, and/or cohesion and/or adhesion, excluding paper or productswhich are woven, knitted, tufted stitch bonded incorporating bindingyarns or filaments, or felted by wet milling, whether or notadditionally needled. The fibers may be of natural or man-made origin.They may be staple or continuous filaments or may be formed in situ.Depending on the method for forming the web, the nonwoven fabric usuallyincludes a composite nonwoven fabric, a needle-punched nonwoven fabric,a melt-blown nonwoven fabric, a spun bonded nonwoven fabric, a dry-laidnonwoven fabric, a wet-laid nonwoven fabric, a stitch-bonded nonwovenfabric, or a spun lace nonwoven fabric. The fabric layer provides a softhand feel similar to real leather.

In one embodiment of the disclosure, the fiber layer comprises aplurality of fibers. Preferably, the fibers are made of at least onematerial selected from the group consisting of polyene, polyamide,poly(p-phenylene terephthalamide), polyolefin, polymethyl methacrylate(PMMA), polyethylene terephthalate (PET), polytrimethylene terephthalate(PTT), polybutylene terephthalate (PBT), polyacrylonitrile (PAN), and amixture thereof.

FIG. 2 illustrates a cross-sectional view of an artificial leather 2according to a second embodiment of the present disclosure. Theartificial leather 2 also includes a fabric layer 21 and an EPM layer,while the EPM layer is an EPM composite layer 22. The EPM compositelayer 22 includes an EPM foaming layer 221 and an EPM surface layer 222.The fabric layer 21 is attached to the EPM foaming layer 221. The EPMsurface layer 222 is disposed on a surface of the EPM foaming layer 221opposite to the fabric layer 21. That is, the EPM foaming layer 221 hasa first surface and a second surface opposite to the first surface. Thefabric layer 21 is attached to the first surface of the EPM foaminglayer 221, and the EPM surface layer 22 is disposed on the secondsurface of the EPM foaming layer 221.

In one preferred embodiment of the present disclosure, a manner offoaming the EPM foaming layer may be chemically foaming or physicallyfoaming, wherein the chemically foaming manner uses an agent capable ofconducting a chemical reaction to yield gas, with the gas evenlydistributed in the EPM. In another aspect, the physically foaming mannerincludes infiltrating gas or supercritical carbon dioxide into the EPM,and making the gas evenly distributed in the EPM by stirring to form theEPM foaming layer. Since the EPM foaming layer includes foaming pores,it is capable of replacing the polyurethane used in the conventionalartificial leather, especially the wet-process polyurethane. The EPMfoaming layer can provide a thick and rich hand feel similar to thewet-process polyurethane. In another aspect, since the density of theEPM is less than the density of the polyurethane used in conventionalartificial leather, the EPM is lighter in weight at the same thickness.Preferably, the foaming density reduction rate (density afterfoaming/density before foaming) of the EPM foaming layer is about 40% toabout 90%.

In one preferred embodiment of the present disclosure, the EPM foaminglayer includes a plurality of independent pores. In another aspect, adiameter of the pores in the EPM foaming layer is about 20 μm to about150 μm, preferably about 50 μm to about 120 μm, and more preferablyabout 70 μm to about 100 μm. As such, the EPM foaming layer is capableof providing a thick, rich and bouncy hand feel similar to realleathers.

In one preferred embodiment of the present disclosure, the EPM foaminglayer has a thickness of about 0.10 mm to about 0.70 mm, preferably 0.25mm to about 0.55 mm, and more preferably about 0.30 mm to about 0.40 mm.A hardness of the EPM foaming layer is about 50 A to about 80 A,preferably about 55 A to about 75 A, and more preferably about 60 A toabout 70 A. A melting point of the EPM foaming layer is about 60° C. toabout 200° C., preferably about 100° C. to about 190° C., and morepreferably about 130° C. to about 170° C.

In one preferred embodiment of the present disclosure, the EPM surfacelayer presents a texture on a surface opposite to the EPM foaming layer.That is, the EPM surface layer has a first surface facing the EPMfoaming layer and a second surface opposite to the first surface. Thetexture is presented on the second surface of the EPM surface layer. Amethod for forming the texture may include transfer printing using arelease material or a mold having a corresponding texture, but is notlimited thereto.

In one preferred embodiment of the present disclosure, a thickness ofthe EPM surface layer is about 0.10 mm to about 0.50 mm, preferablyabout 0.20 mm to about 0.40 mm, and more preferably 0.30 mm to about0.35 mm. A hardness of the EPM surface layer is 50 A to about 95 A,preferably about 55 A to about 80 A, and more preferably about 65 A toabout 75 A. A melting point of the EPM surface layer is about 60° C. toabout 200° C., preferably about 100° C. to about 190° C., and morepreferably about 130° C. to about 170° C.

In one preferred embodiment of the present disclosure, a ratio of thethickness of the EPM surface to the thickness of the EPM foaming layeris about 9:1 to about 1:9, preferably about 5:1 to about 1:5, and morepreferably about 3:1 to about 1:3.

In one preferred embodiment of the present disclosure, the EPM layerfurther includes an EPM adhesive layer, and the fabric layer is attachedto the EPM layer through the EPM adhesive layer. FIG. 3 illustrates across-sectional view of an artificial leather 3 according to a thirdembodiment of the present disclosure. The artificial leather 3 alsoincludes a fabric layer 31 and an EPM layer, while the EPM layer is anEPM composite layer 32. The EPM composite layer 32 includes an EPMfoaming layer 321, an EPM surface layer 322, and an EPM adhesive layer323. The fabric layer 31 is attached to the EPM layer (e.g., the EPMcomposite layer 32) through the EPM adhesive layer 323. For example, thefabric layer 31 is attached to the EPM foaming layer 321 by the EPMadhesive layer 323, and the EPM surface layer 322 is disposed on asurface of the EPM foaming layer 321 opposite to the fabric layer 31.That is, the EPM adhesive layer 323 and the EPM surface layer 322 arerespectively disposed on two opposite surfaces of the EPM foaming layer321. Preferably, the EPM adhesive layer 323 is a hot-melt adhesive.

In one preferred embodiment of the present disclosure, a hardness of theEPM adhesive layer is about 50 A to about 85 A, preferably about 55 A toabout 80 A, and more preferably about 60 A to about 75 A. A meltingpoint of the EPM adhesive layer is about 50° C. to about 140° C.,preferably about 55° C. to about 130° C., and more preferably about 60°C. to about 110° C.

In another preferred embodiment of the present disclosure, the fabriclayer is attached to the EPM foaming layer by another adhesive layer.Preferably, the other adhesive layer is a hot-melt adhesive, morepreferably a hot-melt adhesive of EPM. That is, the adhesive layer maynot be a part of the EPM layer or the EPM composite layer.

In one preferred embodiment of the present disclosure, the artificialleather further includes a covering layer disposed on a surface of theEPM layer opposite to the fabric layer. That is, the EPM layer has afirst surface and a second surface opposite to the first surface. Thefabric layer is attached to the first surface of the EPM layer, and thecovering layer is disposed on the second surface of the EPM layer. FIG.4 illustrates a cross-sectional view of an artificial leather accordingto a fourth embodiment of the present disclosure. The artificial leather4 includes a fabric layer 41, an EPM layer (e.g., an EPM composite layer42) and a covering layer 43. The EPM composite layer 42 includes an EPMfoaming layer 421, an EPM surface 422, and an EPM adhesive layer 423.The fabric layer 41 is attached to the EPM foaming layer 421 by the EPMadhesive layer 423, and the EPM surface layer 422 is disposed on asurface of the EPM foaming layer 421 opposite to the fabric layer 41.The covering layer 43 is disposed on a surface of the EPM surface layer422 opposite to the EPM foaming layer 421 or the fabric layer 41. Inanother embodiment of the present disclosure, the EPM composite layermay only include, or be composed of, an EPM foaming layer and an EPMsurface layer.

The covering layer of the present disclosure includes, but is notlimited to, polyurethane, thermoplastic polyurethane, polyolefin orthermoplastic polyolefin. Preferably, the polyurethane is an aqueouspolyurethane. The covering layer may optionally present textures or havemicrostructures on its surface, or may include pigments.

As described above, the artificial leather of the present disclosure ismainly made of EPM. When the fabric layer made of polyolefin is used,the artificial leather is completely made of polyolefin materials, andthus is completely recyclable. Furthermore, the artificial leather ofthe present disclosure has leather-like hand feel, and excellentphysical properties and abrasion resistance. The torsion resistancestrength of the artificial leather can reach 2.5 kgf/cm or more.Compared with natural leather or conventional artificial leather, theartificial leather of the present disclosure is light-weight and soft,and is suitable for all kinds of applications, especially shoes.

The present disclosure further provides a method for manufacturing theaforementioned artificial leather, including: providing the fabriclayer; providing the EPM layer; and attaching the EPM layer to thefabric layer.

In one preferred embodiment of the present disclosure, the EPM layer isan EPM composite layer including an EPM foaming layer and an EPM surfacelayer. The method includes forming the EPM foaming layer and the EMPsurface layer concurrently.

In one embodiment of the present disclosure, “forming the EPM foaminglayer and the EMP surface layer concurrently” may be achieved byco-extruding the EPM foaming layer and the EPM surface layer. Theco-extrusion process includes, but is not limited to, drying thematerials of the EPM foaming layer and/or the EPM surface layer; meltingthe aforementioned materials; co-extruding the materials using a die(e.g., a T-die); and cooling the materials to a predetermined thickness.In one embodiment of the present disclosure, a release material may beapplied to a surface of the EPM layer during the co-extrusion process(e.g., before the cooling step), such that the surface texture of therelease material can be transfer printed on the EPM surface layer.

In one preferred embodiment of the present disclosure, the EPM compositelayer further includes an EPM adhesive layer. Accordingly, the methodmay include co-extruding the EPM foaming layer, the EPM surface layerand the EPM adhesive layer.

In one preferred embodiment of the present disclosure, the EPM adhesivelayer is a hot-melt adhesive. The method includes heat press laminatingthe EPM adhesive layer to the fabric layer, such that the EPM compositelayer is attached to the fabric layer through the EPM adhesive layer.

In one preferred embodiment of the present disclosure, the methodincludes extrusion laminating the EPM foaming layer to the fabric layer,such that the EMP layer (e.g., the EPM composite layer) is attached tothe fabric layer.

In one preferred embodiment of the present disclosure, the methodincludes attaching the EPM layer to the fabric layer by another adhesivelayer. Preferably, the other adhesive layer is a hot-melt adhesive, morepreferably a hot-melt adhesive of EPM.

In one preferred embodiment of the present disclosure, the methodfurther includes providing a covering layer, and attaching the coveringlayer to a surface of the EPM layer opposite to the fabric layer.

The method of the present disclosure can avoid the use of organicsolvents in the manufacturing process of the conventional artificialleather. Hence, the method of the present disclosure meets the 2020 ZDHC(Zero Discharge of Hazardous Chemicals) requirements. Furthermore, themethod of the present disclosure is simpler and faster than theconventional wet process.

The present disclosure further provides a shoe structure including theaforementioned artificial leather. For example, the artificial leathermay be a part of or the entire shoe upper in the shoe structure. Thatis, the artificial leather a can be combined with the sole and otherparts to form the shoe structure.

The following examples are given to illustrate the method formanufacturing the conjugated fiber of the present disclosure, but arenot intended to limit the scope of the present invention.

Example 1

Drying condition: The EPM was dried to a moisture content of about 300ppm or lower.

Extruder Temperature:

EPM surface layer (component A): 170° C., 200° C., 200° C.

The temperature of the T-die was set at 185° C.

The EPM surface layer was extrusion laminated to a nonwoven fabric, andwas cooled by cooling rollers. The speed of the laminating rollers wasset at 3.0 m/min, thus forming an artificial leather of EPM having athickness of about 0.8 mm.

Then, the artificial leather was pressed by embossing rollers having asurface temperature of 100° C., thus forming the surface-texturedartificial leather of EPM.

Example 2

Drying condition: The EPM was dried to a moisture content of about 300ppm or lower.

Extruder Temperature:

EPM surface layer (component A): 170° C., 200° C., 200° C.

EPM foaming layer (component B): 150° C., 195° C., 190° C., with 1% to5% microsphere foaming agent added.

The temperature of the T-die was set at 185° C.

The metering pumps of the component A and the component B were set sothat the thickness ratio of the EPM surface layer and the EPM foaminglayer was 1:3.

The EPM surface layer and the EPM foaming layer were cooled bylaminating rollers. The speed of the laminating rollers was set at 3.0m/min, thus forming an EPM composite layer (including the EPM surfacelayer and the EPM foaming layer) having a thickness of about 0.4 mm. Thethickness of the EPM surface layer was about 0.1 mm, and the thicknessof the EPM foaming layer was about 0.3 mm.

The EPM composite layer was attached to a polyolefin nonwoven fabric by0.1 mm EPM hot-melt adhesive, thus forming the artificial leather. Theattaching process was conducted using a heat roll laminator with a rollsurface temperature of 100° C.

Example 3

Drying condition: The EPM was dried to a moisture content of about 300ppm or lower.

Extruder Temperature:

EPM surface layer (component A): 170° C., 200° C., 200° C.

EPM foaming layer (component B): 150° C., 195° C., 190° C., with 1% to5% microsphere foaming agent added.

EPM adhesive layer (component C): 150° C., 185° C., 180° C.

The temperature of the T-die was set at 185° C.

The metering pumps of the component A, the component B and the componentC were set, so that the thickness ratio of the EPM surface layer, theEPM foaming layer and the EPM adhesive layer is 1:7:1.

The EPM surface layer, the EPM foaming layer and the EPM adhesive layerwere cooled by laminating rollers. The speed of the laminating rollerswas set at 2.5 m/min, thus forming an EPM composite layer (including theEPM surface layer, the EPM foaming layer and the EPM adhesive layer)having a thickness of about 0.9 mm. The thickness of the EPM surfacelayer was about 0.1 mm, the thickness of the EPM foaming layer was about0.7 mm, and the thickness of the EPM adhesive layer was about 0.1 mm.

A water-based polyurethane covering layer was applied to the EPM surfacelayer.

The EPM composite layer was attached to a polyolefin nonwoven fabricthrough the 0.1 mm EPM adhesive layer, thus forming the artificialleather. The attaching process was conducted using a heat roll laminatorwith a roll surface temperature of 100° C.

Example 4

Extruder Temperature:

EPM surface layer (component A), containing 0%, 10%, 20%, 30%, 50%thermoplastic vulcanize (TPV): 180° C., 210° C., 210° C.

The temperature of the T-die was set at 195° C.

The EPM surface layer was extrusion laminated to a nonwoven fabric, andwas cooled by cooling rollers. The speed of the laminating rollers wasset at 3.0 m/min, thus forming an artificial leather of EPM having athickness of about 0.8 mm.

The artificial leather was further pressed by embossing rollers having asurface temperature of 100° C., thus forming the surface-texturedartificial leather of EPM.

The EPM containing TPV with different contents (as shown below) canprovide the artificial leather with improved mechanical properties andhand feel.

Test Result of Example 4

TPV content 0% 10% 70% 30% 50% Peel strength 3.2 3.5 3.7 3.4 3.8 (kg/cm)Flex fatigue 5,000 20,000 50,000 80,000 100,000 resistance (cycles)

While the present disclosure has been described and illustrated withreference to specific embodiments thereof, these descriptions andillustrations are not limiting. It should be understood by those skilledin the art that various changes may be made and equivalents may besubstituted without departing from the true spirit and scope of thepresent disclosure as defined by the appended claims. The illustrationsmay not necessarily be drawn to scale. There may be distinctions betweenthe artistic renditions in the present disclosure and the actualapparatus due to manufacturing processes and tolerances. There may beother embodiments of the present disclosure which are not specificallyillustrated. The specification and drawings are to be regarded asillustrative rather than restrictive. Modifications may be made to adaptto a particular situation, material, composition of matter, method, orprocess in accordance with the objective, spirit and scope of thepresent disclosure. All such modifications are intended to be within thescope of the claims appended hereto. While the methods disclosed hereinhave been described with reference to particular operations performed ina particular order, it will be understood that these operations may becombined, sub-divided, or re-ordered to form an equivalent methodwithout departing from the teachings of the present disclosure.Accordingly, unless specifically indicated herein, the order andgrouping of the operations are not limitations of the presentdisclosure.

What is claimed is:
 1. An artificial leather, comprising: a fabriclayer; and an ethylene-propylene copolymer (EPM) layer attached to thefabric layer, wherein the EPM layer is an EPM composite layer comprisingan EPM foaming layer and an EPM surface layer.
 2. The artificial leatherof claim 1, wherein the fabric layer is attached to the EPM foaminglayer, and the EPM surface layer is disposed on a surface of the EPMfoaming layer opposite to the fabric layer.
 3. The artificial leather ofclaim 1, wherein the EPM surface layer presents a texture on a surfaceopposite to the EPM foaming layer.
 4. The artificial leather of claim 1,wherein the EPM composite layer further comprises an EPM adhesive layer,and the fabric layer is attached to the EPM composite layer through theEPM adhesive layer.
 5. The artificial leather of claim 1, furthercomprising a covering layer disposed on a surface of the EPM layeropposite to the fabric layer.
 6. A method for manufacturing theartificial leather of claim 1, comprising: providing the fabric layer;providing the EPM layer; and attaching the EPM layer to the fabriclayer.
 7. The method of claim 6, comprising forming the EPM foaminglayer and the EMP surface layer concurrently.
 8. The method of claim 6,comprising co-extruding the EPM foaming layer and the EPM surface layer.9. The method of claim 6, wherein the EMP composite layer furthercomprises an EPM adhesive layer, and the method comprises co-extrudingthe EPM foaming layer, the EPM surface layer and the EPM adhesive layer.10. The method of claim 9, wherein the EPM adhesive layer is a hot-meltadhesive, and the method comprises heat press laminating the EPMadhesive layer to the fabric layer, such that the EPM composite layer isattached to the fabric layer through the EPM adhesive layer.
 11. Themethod of claim 6, comprising extrusion laminating the EPM foaming layerto the fabric layer.
 12. The method of claim 6, further comprisingproviding a covering layer, and attaching the covering layer to asurface of the EPM layer opposite to the fabric layer.
 13. A shoestructure comprising the artificial leather of claim
 1. 14. A shoestructure comprising the artificial leather of claim
 2. 15. A shoestructure comprising the artificial leather of claim
 3. 16. A shoestructure comprising the artificial leather of claim
 4. 17. A shoestructure comprising the artificial leather of claim 5.